The present invention relates to a buildup device that builds up plate-shaped cores stamped out after rotating each of the cores.
In recent years, increase in demand for mass production of built-up cores has required a buildup device capable of building up cores at high speed when built-up cores are produced by building up plate-shaped cores to increase production efficiency. To achieve the buildup device capable of building up cores at high speed, JP-A-2011-62732 discloses a structure as follows: a side face of a built-up iron core is supported by an inner wall surface of a lower mold; a surface of a lowermost core of the built-up iron core is supported by a back pressure device; the inner wall surface of the lower mold is rotatably coupled to a first rotary drive device; and the back pressure device is coupled to a second rotary drive device. The structure of JP-A-2011-62732 allows the built-up iron core to be rotated by the first rotary drive device and the second rotary drive device after a punch attached to an upper mold passes through a die of the lower mold, thereby aggressively rotating the built-up iron core built up by rotation of a pressure receiving portion of the back pressure device to increase rotation speed.
However, if operation at high speed is attempted in a conventional typical buildup device by increasing rotation speed of a rotary drive device, a load is applied to a motor and other components, and thus the load may cause breakage or failure in the motor or the like. To reduce a load to be applied to a rotating and sliding portion, JP-A-2013-116497 discloses an ejection hole that is provided in a die metal holder rotatably supporting a die holder to supply compressed air to the die holder through the ejection hole to apply floating force to the die holder, thereby building up a core after rotating the core while rotation supply to the die holder is reduced.
However, in the buildup device of JP-A-2013-116497 in which compressed air is supplied to allow the die holder to smoothly rotate during building up a core after rotating the core so that frictional resistance in the rotating and sliding portion is reduced to reduce a load, there is a problem in which a load caused by the frictional resistance can be reduced, but a load applied to a motor and other components caused by vibration in operation at high speed cannot be efficiently reduced.
In this way, the conventional buildup device has a problem in which if a rotary drive unit is attempted to be rotated at high speed, a load caused by vibration increases, and if the load caused by vibration is attempted to be reduced, rotation speed of the rotary drive unit needs to be reduced. Thus, there is required a buildup device capable of reducing a load caused by vibration, to be applied to a motor and the like, while achieving high speed rotation of the rotary drive unit.
The present invention solves the problem above and provides a buildup device that has a less load applied to other components such as a motor, and that is capable of laminating plate-shaped cores at high speed.